Prius Gen2 adapter board development thread

[MattsAwesomeStuff]

I vote inside, I like to have nice and tidy builds because I never actually put the effort into doing that myself.

However, this isn't a democracy, it's a do-ocracy and my vote shouldn't matter because I'm not the one doing the work :p

[konstantin8818]

I wonder how complicated and expensive is to make a DC-DC power source for main board, to power it from HV system?
Like it is made in Curtis or PowerWatcher. You dont need a 12V system at all. I know it is mondatory for EVs, but if something went wrong with it, 12V battery is dead, but HV is good and you need to go. Without 12V main board won't start and Inverter's DC-DC converter will not either. But if both powered by HV system, it is not an issue.

[SciroccoEV]

I wonder how complicated and expensive is to make a DC-DC power source for main board, to power it from HV system?
Like it is made in Curtis or PowerWatcher. You dont need a 12V system at all. I know it is mondatory for EVs, but if something went wrong with it, 12V battery is dead, but HV is good and you need to go. Without 12V main board won't start and Inverter's DC-DC converter will not either. But if both powered by HV system, it is not an issue.

Any off the shelf switch mode power supply with a wide input range would do the job. Marginally better performance can be gained by bypassing the input bridge rectifier.

The General Motors EV1 was unique amongst production EVs in copying the 'bootsrap' system that some amateur converters were using. It had a push button under the dash that would bypass the relays feeding power to the DC/DC and get you 12v DC even if you'd flattened the aux. battery.

[RetroZero]

Don't know what happened to my post, but to be short..If it's mandatory, stick with it. Regulations will only get tighter in the future, so I suggest running as much OEM units as intended. This is a critical safety item for the automotive world(ABS and warnig/hazard lights), and changing it can open a very nice can of worms on inspection day

[konstantin8818]

Don't know what happened to my post, but to be short..If it's mandatory, stick with it. Regulations will only get tighter in the future, so I suggest running as much OEM units as intended. This is a critical safety item for the automotive world(ABS and warnig/hazard lights), and changing it can open a very nice can of worms on inspection day

Yup, about strict regulations... You definitely don't know how things done here in Belarus...
For today there are only ~400 EVs registered here... Few engineers know how to deal with them.
And I didn't say that I need to remove 12V system, the idea of bypassing it when needed is pretty cool.

[johu]

I think it is past the scope of the Prius control board. If you want something like this, do like SciroccoEV says and deploy an SMPS somewhere in the car

[Kevin Sharpe]

Regulations will only get tighter in the future, so I suggest running as much OEM units as intended. This is a critical safety item for the automotive world(ABS and warnig/hazard lights), and changing it can open a very nice can of worms on inspection day

This is a very good point. If you make the unit external we are more likely to get it approved for use in commercial applications going forward

I would also suggest you treat this as a VCU not just an inverter controller. The easier we can make conversions for people the more likely we are to see lots vehicles on the road

[konstantin8818]

Well, I just asked. Thanks everyone for suggestions

[RetroZero]

kiwifiat wrote:
"Anyone starting from scratch and lacking the required electronics skills has the option of the rev3 board as it has everything already onboard to run both induction and pmsm's"

Would it be hasty to go out and order the rev3 board and stripboard kit? I think I could manage a simple adapter circuit if there are schematics. Reason being, whilst this awesome Adapter board/VCU is being created, I would like to get my transaxle spinning. Once 'done', I can focus on dismantle of transaxle for Mg1&Mg2 lock-up 'kit'. I fear the 'Damien weld solution' will not pass certification here, so will have something made up that could then be used by others.

[RetroZero]

Johu wrote: "Final question: does anyone feel like making a ModICE compatible adapter board in KiCAD? I can draw the schematic if needed."

Is there anyone that could do this, or is Johu still working on how to incorporate all the functions?

Getting a bit confusing again, with following Gen2 Inverter Controller link at the same time. I understand that Brainboard V3 is compatible for motor spin only, BUT adapter board would allow for charging via Mg1 AND DC/DC for 12v auxillary circuits.
in short - if I want to get motor spin, only need Brainboard V3. If I want charging and DC/DC as well, wait for new baord (2mm narrower) with adapter board. Yes?

[johu]

Well you can't run the Prius inverter off a V3 main board as is.
1. At the very least you need 3 NPN transistors that operate the 12V PWM signals.
2. Next you need to convert the bipolar -15V to +15V current feedback signals to 0-3.3V. A circuit has been posted earlier. You need MG2 current feedback for running FOC.
3. You need the blended in MG1 current feedback for charge mode (measure AC input current).
4. Then you can map one of the low side PWM signals, again via an NPN transistor, to the buck converter to allow HV battery charging.

The DC/DC converter, as in HV to 12V, will not be connected to the adapter board. It just needs a 12V control signal.
So 1. is enough for controlling an asynchronous motor with sine firmware
2. Is enough for controlling a synchronous motor with FOC firmware
3. and 4. are needed for charging.

[RetroZero]

Thanks Johu, as I am trying to use Gen 2 transaxle, will need 2. I would like to spin motor for a presentation, so is it possible to have schematics from somewhere for 3 and 4 that I could build with strip board kit and order the Brainboard V3? I am trying to get funding from my region council to promote this setup as viable solution, so would like to know easiest /quickest way forward. Thanks for reply

[konstantin8818]

Well you can't run the Prius inverter off a V3 main board as is.
1. At the very least you need 3 NPN transistors that operate the 12V PWM signals.
2. Next you need to convert the bipolar -15V to +15V current feedback signals to 0-3.3V. A circuit has been posted earlier. You need MG2 current feedback for running FOC.
3. You need the blended in MG1 current feedback for charge mode (measure AC input current).
4. Then you can map one of the low side PWM signals, again via an NPN transistor, to the buck converter to allow HV battery charging.

Aha! So that is where those components, I've bought to build Damien's board will come in handy

[MattsAwesomeStuff]

Well you can't run the Prius inverter off a V3 main board as is. At the very least ...

That's a great breakdown. I didn't have that all in my head yet.

[ZooKeeper]

post deleted

[arber333]

The DC/DC converter, as in HV to 12V, will not be connected to the adapter board. It just needs a 12V control signal.
So 1. is enough for controlling an asynchronous motor with sine firmware
2. Is enough for controlling a synchronous motor with FOC firmware
3. and 4. are needed for charging.

You can use SN74LS06N inverter chip and supply the chip with 12V source. There are 6 ports, 3 of them we use to run IGBTs and rest as we please. Pullups or whatever...

For 3. and 4. I would suggest you use Melexis sensor fixed on the DC rail inside Prius Gen2 inverter. That way you cen have true buck output control from 3phase or boost whatever you need. No need to complicate with MG1 sensor signal conversion. My 5c.

[RetroZero]

Ok, this clears up more of the 'grey areas'. Can I update the wiki for Gen 2 board with this information? I think we're onto something that could serve as a good source before diving into a build.

[konstantin8818]

Ok, this clears up more of the 'grey areas'. Can I update the wiki for Gen 2 board with this information? I think we're onto something that could serve as a good source before diving into a build.

I believe to prevent confusion it should be a separate thread on wiki for the adapter board.

[RetroZero]

How about updating V3 mainboard with additional info?

exemple - " If V3 mainboard is used with Prius Gen2 inverter, additional circuits are required." Adapter board currently in design stage (April 2020)
1. At the very least you need 3 NPN transistors that operate the 12V PWM signals.
2. Next you need to convert the bipolar -15V to +15V current feedback signals to 0-3.3V. You need MG2 current feedback for running FOC.
3. You need the blended in MG1 current feedback for charge mode (measure AC input current).
4. Then you can map one of the low side PWM signals, again via an NPN transistor, to the buck converter to allow HV battery charging.

I also updated Johu's diagram, but don't know how, and did not want to risk updating his wiki page. Could some one check and if OK, can it be updated pls? It is to have clarity on Pin outputs for us non EE people.

Updated Pin header locations

[arber333]

Maybe Johannes could just update Rev3 board with SN74LS06D SOIC version and add 1K resistors to its Y pins.
Then you can use 3x pins to drive IGBTs and couple of pins to drive Buck-Boost. Remaining pin you can use to trigger Fault state by pulling MPROT/FAULT pin low etc...
Sensor pins only need conversion to 3V3 level.

[johu]

You can use SN74LS06N inverter chip and supply the chip with 12V source. There are 6 ports, 3 of them we use to run IGBTs and rest as we please. Pullups or whatever...

For 3. and 4. I would suggest you use Melexis sensor fixed on the DC rail inside Prius Gen2 inverter. That way you cen have true buck output control from 3phase or boost whatever you need. No need to complicate with MG1 sensor signal conversion. My 5c.

I've been successful using the ULN2003 chip. All we need is open collector, no push pull logic needed.

Current sensor wise I thought using the existing sensors would ease the installation. Also when using an external Melexis sensor I would need to add an additional analog input to sample it. I don't think it matters whether the control loop is based on input our output current as they are coupled by a fixed factor anyways (when talking RMS values). When configuring the charger you only have to keep in mind what battery current will result. Say you configure 10A 3-phase (380V) input current it will result in roughly 19A battery current for a 200V battery.

6. If the system functions above 330v, a devider system must be put in place to not surpass(blow up) the 3v3 limit on Pin12

Aha, so we need to support about 600V for rectified 3-phase, thus a 1:2 divider is needed.

I currently wonder if an adapter board is the way forward or whether a bespoke Prius board would be better. After all it just means copy and pasting the V3 design and adding some components around it. Manufacturing-wise the adapter board needs to be made separately anyway.

[Kevin Sharpe]

I currently wonder if an adapter board is the way forward or whether a bespoke Prius board would be better. After all it just means copy and pasting the V3 design and adding some components around it. Manufacturing-wise the adapter board needs to be made separately anyway.

My vote is for a dedicated board. An adaptor board only makes sense in high volumes and has all the issues related to board-to-board connector reliability in an automotive environment.

Having a mechanism for identifying the board type in software could be useful going forward

[jnsaff]

I currently wonder if an adapter board is the way forward or whether a bespoke Prius board would be better. After all it just means copy and pasting the V3 design and adding some components around it. Manufacturing-wise the adapter board needs to be made separately anyway.

Any way this could be incorporated as a universal board that can run both Gen2 and Gen3 inverters (not at the same time ofc)? I know the Gen3 board is meant to go inside the case and there are differences between Prius and Auris/Yaris versions but if the differences are small and Gen2 support can be squeezed onto the Gen3 board that would greatly simplify supply chain. There could also be a case for a split BoM where Gen2 components are not populated if only Gen3 is needed.

[arber333]

Any way this could be incorporated as a universal board that can run both Gen2 and Gen3 inverters (not at the same time ofc)? I know the Gen3 board is meant to go inside the case and there are differences between Prius and Auris/Yaris versions but if the differences are small and Gen2 support can be squeezed onto the Gen3 board that would greatly simplify supply chain. There could also be a case for a split BoM where Gen2 components are not populated if only Gen3 is needed.

You could do it with existing Rev3 boards, but you would have to make a different adapter for Gen2 and Gen3 since inputs are not similar at all.

Hm... You know what? It is not such a bad idea! Considering we would have to make Gen3 board to one size fit all Gen3.
Then vertical space is enough to house one Rev3 board on top of fake Prius master board. Also that board could include Arduino chip to control charger function of Buck boost, keep MG1 transistors down, current sensors signal converter, some small relays and 12V DCDC. Board size can be extended around small connector as i demonstrated before.

Gen2 would require totaly different board which would fit in a separate box, but could still be Rev3 on top of an adapter board. Or maybe just expand Rev3 board to house all sensor inputs... What would be easier.

I have just been informed my prototype boards from HK are delayed in DHL warehouse. Why they dont say... COVID? Maybe would be a good idea to get some local sourced adapter boards. Who knows how long that situation would remain...

[RetroZero]

Yes current Covid does pose problems, but gives me time to focus on having a bench running Gen 2 transaxle and converter. Since transport is practically at a stand still, I was hoping to use readily available local sourced adapter add ons, as designing the additional circuits are above my knowledge level at the moment. But even readily available add ons are a mystery to me.... I'll keep google-ing away and learning all your terminologies. Hope you can put up with my dumb questions along the way... Sorry in avance . By the way, anything Gen 2 and Gen 3 compatible would open up huge potential for kit configurations